Nuprl Lemma : member_filter_2

[T:Type]. ∀L:T List. ∀P:{x:T| (x ∈ L)}  ⟶ 𝔹. ∀x:T.  ((x ∈ filter(P;L)) ⇐⇒ (x ∈ L) ∧ (↑(P x)))


Proof




Definitions occuring in Statement :  l_member: (x ∈ l) filter: filter(P;l) list: List assert: b bool: 𝔹 uall: [x:A]. B[x] all: x:A. B[x] iff: ⇐⇒ Q and: P ∧ Q set: {x:A| B[x]}  apply: a function: x:A ⟶ B[x] universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] all: x:A. B[x] member: t ∈ T so_lambda: λ2x.t[x] prop: and: P ∧ Q so_apply: x[s] implies:  Q top: Top iff: ⇐⇒ Q uimplies: supposing a not: ¬A false: False rev_implies:  Q subtype_rel: A ⊆B guard: {T} or: P ∨ Q bool: 𝔹 unit: Unit it: btrue: tt uiff: uiff(P;Q) ifthenelse: if then else fi  bfalse: ff exists: x:A. B[x] sq_type: SQType(T) bnot: ¬bb assert: b squash: T true: True cand: c∧ B
Lemmas referenced :  list_induction all_wf l_member_wf bool_wf iff_wf filter_wf5 assert_wf list_wf filter_nil_lemma null_nil_lemma btrue_wf member-implies-null-eq-bfalse nil_wf btrue_neq_bfalse assert_witness subtype_rel_dep_function cons_wf subtype_rel_sets cons_member equal_wf subtype_rel_self set_wf filter_cons_lemma eqtt_to_assert eqff_to_assert bool_cases_sqequal subtype_base_sq bool_subtype_base assert-bnot or_wf assert_elim not_assert_elim
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation lambdaFormation cut thin introduction extract_by_obid sqequalHypSubstitution isectElimination hypothesisEquality sqequalRule lambdaEquality functionEquality setEquality cumulativity because_Cache hypothesis setElimination rename functionExtensionality applyEquality productEquality dependent_set_memberEquality independent_functionElimination dependent_functionElimination universeEquality isect_memberEquality voidElimination voidEquality independent_pairFormation independent_isectElimination equalityTransitivity equalitySymmetry productElimination inrFormation comment inlFormation unionElimination equalityElimination dependent_pairFormation promote_hyp instantiate addLevel impliesFunctionality andLevelFunctionality hyp_replacement applyLambdaEquality imageMemberEquality baseClosed imageElimination natural_numberEquality levelHypothesis

Latex:
\mforall{}[T:Type].  \mforall{}L:T  List.  \mforall{}P:\{x:T|  (x  \mmember{}  L)\}    {}\mrightarrow{}  \mBbbB{}.  \mforall{}x:T.    ((x  \mmember{}  filter(P;L))  \mLeftarrow{}{}\mRightarrow{}  (x  \mmember{}  L)  \mwedge{}  (\muparrow{}(P  x)))



Date html generated: 2017_04_14-AM-08_53_08
Last ObjectModification: 2017_02_27-PM-03_38_37

Theory : list_0


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